In order to render Earth imagery data interoperable among a multitude of systems and users, the Motion Imagery Standards Board (MISB) has prescribed a standard format for transmitting and storing images of the Earth derived from down-looking cameras of various sorts at all wavelengths. MISB Standards are summarized in the Motion Imagery Standards Profile, MISP-2015.1: Motion Imagery Handbook (MISB, 2015), which may be accessed at http://www.gwg.nga.mil/, and which is incorporated herein by reference, and may serve, as a normative reference, and where terms might otherwise be ambiguous, for definition of terms as used herein. MISB Standard 0601, in particular, details the Unmanned Air System (UAS) Datalink Local Set (LS) for UAS platforms. MISB Standard 0601 incorporates NITF Standards document MIL-STD-2500C of the National Imagery Transmission Format (NITF), which is also incorporated herein by reference.
MISB standards apply to any type of imaging data, such as Visible Light, Infrared, LIDAR cloud, RADAR return, Acoustical, or any type of data, from any type of modality, as do all of the teachings of the present invention.
Corner points (synonymously referred to herein as “vertices”) are transmitted as metadata (tags 26-33, according to the NITF standard cited above) within packets encapsulating motion imagery obtained from an airborne platform. The ordering of identified vertices of frames of imaging data may become corrupted during various stages of transmission or processing, but must accord with MISB standards for correct projection of imaging data onto Earth coordinates. While there are various ways to detect irregularities in the orientation of frame vertices and to correct them, some of which are routinely practiced, in order for images at any facet of the processing stream to be useful, irregularities in the orientation of frame vertices must be efficiently detected and cured. Since video frames occur at a high rate, it is necessary to detect and correct such irregularities rapidly. A new and particularly efficient method for detecting and curing such irregularities is provided herein, in accordance with embodiments of the present invention as taught below.